// Adds target=_blank to links to allow external links to validate under XHTML 1.0 Strict
// example link: <a href="document.html" rel="external">external link</a>
function externalLinks() { 
  if (!document.getElementsByTagName) return; 
  var anchors = document.getElementsByTagName("a"); 

  for (var i=0; i<anchors.length; i++) { 
    var anchor = anchors[i]; 
    if (anchor.getAttribute("href") && anchor.getAttribute("rel") == "external") 
      anchor.target = "_blank"; 
  } 
} 

window.onload = externalLinks;